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Deverchere, Jacques; Yelles, K; Domzig, Anne; Mercier De Lepinay, B; Bouillin, J.p.; Gaullier, V; Bracene, R; Calais, E; Savoye, Bruno; Kherroubi, A; Le Roy, P; Pauc, H; Dan, Gabriela. |
[1] We investigate the active seismogenic fault system in the area of the 2003 Mw 6.9 Boumerdes earthquake, Algeria, from a high-resolution swath bathymetry and seismic survey. A series of 5 main fault-propagation folds similar to20-35 km long leave prominent cumulative escarpments on the steep slope and in the deep basin. Fault activity creates Plio-Quaternary growth strata within uplifted areas such as a rollover basin on the slope and piggyback basins in the deep ocean. Most thrusts turn to fault-propagation folds at the sub-surface and depict ramp-flat trajectories. We find that the two main slip patches of the 2003 Mw 6.9 Boumerdes earthquake are spatially correlated to two segmented cumulative scarps recognized on the slope and at the foot of the... |
Tipo: Text |
Palavras-chave: Continental margin; Sismicity; Tectonophysics. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-743.pdf |
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Dan, Gabriela; Sultan, Nabil; Savoye, Bruno; Deverchere, Jacques; Yelles, Karim. |
The Algerian margin is a seismically active region, where during the last century, several large magnitude earthquakes took place. This study combines geotechnical and sedimentological data with numerical modelling to quantitatively assess the present-day slope stability of the Algerian margin. Geotechnical laboratory tests, such as cyclic triaxial tests, oedometric tests and vane shear tests were carried out on sediment cores collected on the study area. The liquefaction potential of a sediment column located about 30 km from the BoumerdSs earthquake epicentre of 21st May 2003 was evaluated theoretically for an earthquake of M (w) = 6.8. We show that thin sand and silt beds such as those described on recovered sediment cores are the main cause of sediment... |
Tipo: Text |
Palavras-chave: Earthquakes; Potential of liquefaction; Slope stability; Algerian margin. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6448.pdf |
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Dan, Gabriela; Sultan, Nabil; Savoye, Bruno. |
In 1979, a catastrophic event occurred on the Nice continental slope (French Riviera) generating the lost of human lives and important material damages. Part of the new harbour constructed at the edge of the International Airport of Nice collapsed into the sea. The main aim of this work was 1) to present a review of facts and details related to the 1979 accident and a review of the geological setting, and 2) to evaluate the slope stability before and after the new harbour construction, by taking into account new available data such as sediment cores and piezocone CPTU data. The CPTU data were of great value to understand the origin of the 1979 event. They show the existence of a sensitive clay bed between 30 mbsf and 45 mbsf Under high deviatoric load a... |
Tipo: Text |
Palavras-chave: Finite element method; Trigger mechanism; Slope stability; Nice 1979 event. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3507.pdf |
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Dan, Gabriela; Sultan, Nabil; Cattaneo, Antonio; Deverchere, J; Yelles, K. |
On 21st May 2003, a damaging earthquake of Mw: 6.9 struck the region of Boumerdès 40 km east of Algiers in northern Algeria. The seismic shocks had devastating effects in the offshore area between the cities of Algiers and Dellys, where numerous cable breaks were observed. The submarine area encompassing the 2003 Boumerdès epicenter (central Algerian margin) was recently investigated using geophysical and sampling tools. It has been observed that small-size slides and mass-transport deposits occur across this area. Thus, a detailed analysis was performed on 25 submarine slides identified in water depth from 500 m to 2700 m, by measuring different morphological parameters (i.e. surface, head-scarp height, slope in the source area and in adjacent... |
Tipo: Text |
Palavras-chave: Triggering mechanism; Morphology; Mass transport deposit; Algeria. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/acte-6453.pdf |
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